class_docstr: Implements soft-termination (zero discount) on life loss.
docstr: Initializes a new `_ZeroDiscountOnLifeLoss` wrapper.
  
  Args:
    environment: An Atari environment.
  
  Raises:
    ValueError: If the environment does not expose a lives observation.
docstr_tok: ["Initializes","a","new","`","_ZeroDiscountOnLifeLoss","`","wrapper",".","Args",":","environment",":","An","Atari","environment",".","Raises",":","ValueError",":","If","the","environment","does","not","expose","a","lives","observation","."]
code: def __init__(self, environment: dm_env.Environment):
      """Initializes a new `_ZeroDiscountOnLifeLoss` wrapper.
  
      Args:
        environment: An Atari environment.
  
      Raises:
        ValueError: If the environment does not expose a lives observation.
      """
      super().__init__(environment)
      self._reset_next_step = True
      self._last_num_lives = None
  
imports: import abc
  from typing import Tuple, List, Optional, Sequence, Union
  from acme.wrappers import base
  from acme.wrappers import frame_stacking
  import dm_env
  from dm_env import specs
  import numpy
  from PIL import Image
label_desc: Use image node_id 1 to create a new _ZeroDiscountOnLifeLoss object from inherited base classes: base with example: obj = _ZeroDiscountOnLifeLoss(environment)